Rolling mill



March 1, 1932. c, G|BBON$ 1,847,713

ROLLING MILL Fileq May 17, 1928 3 Sheets-Sheet l Maych 1, 1932. c. .1GIBBONS ROLLING MILL s Sheets-Sheet 2 Filed May 17, 1928 March 1, 1932.C. J. GIBBONS ROLLING MILL Filed May 1'7. 1928 3 Shests-Sheet 5 n, o m

l st-Tented Mar. 1, 1932 UNITED STATES CHARLES J. GIBBONS, OFBRIDGEPORT, CONNECTIGU '1 ROLLING MILL Application filed May 17,

This invention relates to rolling mills particularly mills for rollingsheets or flat strips of metal, and has for an object to provide arolling mill in which large reductions may be secured if desired or inwhich an improved finish may be given.

It is also an object of the invention to provide a rolling mill in whichstocks of strips or sheets may be rolled without their welding or 1sticking together.

It is another object of the invention to provide a rolling mill in whichthe rolls may be driven positively and in which a thin strip of metalmay be drawn through the roll by means independently of the roll drive.

lVith the foregoing and other objects in view the invention consists incertain novel features of construction, combinations and arrangements ofparts as will be more fully described in connection with theaccompanying drawings. In these drawings,

Fig. l is an end elevation of a rolling mill and associated elementsembodying my invention.

Fig. 2 is a diagrammatical front elevation of a rolling mill embod ingmy invention, certain parts being bro en away to more .clearly show theconstruction and also showing a different arrangement of drive than thatshown in Fig. 1.

Fig. 3 is a detail section substantially on line 3--3 of Fig. 2.

Fig. 4 is a partial plan view and a partial section showing somewhatdiagrammatically a device for drawing the metal through the rolls.

Fig. 5 is a. diagrammatic endelevation of a four-high mill involving myinvention, and

Fig. 6 is a similar View of a three-high mill embodying my invention.

Referring to Fig. 1, the rolls are mounted in a pair of suitablehousings 10 and the mill. shown is afour-high mill similar to thearrangement of rolls shown in Fig. It in volves upper and lower workrolls 11 and 12 respectively each of which has a backing roll 13 ofconsiderably larger diameter to back up and support the work roll. Asshown the work rolls are of comparatively small diam eter, andtherefore, do not have the requisite 1928. Serial No. 278,385.

strength and stiffness to withstand the heavy pressures required for therolling operation and to give the large reduction desired and also toinsure uniform gauge for the rolled strip. The large backing rolls 13give this required strength and stiffness, the rolls 11 and 12 runningon the surfaces of these backing rolls as indicated, which thus ineffect provide roller bearings for the work rolls. The necks 14 of thebacking rolls 13 are mounted in suitable hearings in the housings, andin order to reduce the resistance in turn oi these rolls these necks aremounted in roller bearings 15 so that there is no slippage between thework rolls and the backing rolls. It is preferred to make the work rolls11 and 12 of diflterent diameters, and it is also preferred that thesmallerroll be the upper roll for greater convenience in rolling,although the same effect as far as preventing sticking of the sheets ofthe stack is secured'if the smaller roll is the lower roll.

In rolling hot sheets in stacks, that is piled one above the other, ifthe work rolls are the same size considerable trouble is experienced bythe sheets in the stack, indicated at 16, Fig. 5, sticking or weldingtogether during the rolling operation so that it is difficult toseparate them and it may be impossible to do this without spoiling thesheets. I have found that by making the two work rolls of diflerentdiameters that this sticking or welding elfect is obviated even thoughthe two rolls are driven at the same surface speed. This appears to beefi'ected by the fact. that diiferent diameters of working rolls have aslightly different effect or give different movements to the metal intheir adjacent strips caused by the differences of the curvature ofcontact or the angle of contact'of the two rolls with the metal so thatthere is a slight slippage between the adjacent surfaces of the stripswhich prevents their welding or sticking, and this is true even if thereare more than two sheets rolled at a time. There is also 21 tendency ofthe different sheets adjacent the rolls following around the rolls asthey issue from between them which still further assists in. preventingtheir sticking. Either the work rolls or the backing rolls may bedriven, 10o

. backing roll for it especially if it is used for relatively narrowstrips as the roll may have sufiicient stren th. I have shown thisarrangement in I ig. 6 in which there is no backing roll for the lowerwork roll 12 of larger diameter, but there is a backing roll 13 for thesmaller roll 11. Boiler bearings 17 may also be provided or the workrolls if desired.

These rolls may also be used as a drawing mill, that is, a strip ofmetal may be drawn between the work rolls by a separate mechanism. Thisdrawing device is shown in Figs.

1 and 4. It comprises a blocker having a rotary drum or block 18 drivenby any suitable means, such as a friction clutch 19 associated with agear 20 driven through a pinion 21. from a motor 22, and this block isso geared that it will draw the metal through the rolls at a greaterspeed than would the metal move under the action of the rolls whendriven from their usual drive. In order to permit the rolls, therefore,to speed up a one-way drive is provided for the work rolls, that is,there is a ositive drive of these rolls in one direction, at this drivewill ermit the rolls to rotate faster under the action of the strip. Itis preferred also that the block 18 be an automatic block toautomatically grip the strip of metal 23 as soon as the end thereofreaches the block. In the arrangement shown in Fig. 1 there is a geardrive for each of the work rolls 11 and 12, the drive for the roll 11being shown as gear 24 and for the roll 12 as gear 25 on opposite sidesof the housings and connected to opposite ends of the rolls, and bothdriven from a power shaft 26 by suitable gearing. Of course, this gearing will be proportioned to drive the two rolls at substantially thesame surface speed. The one-way drive from each gear 24 or 25 to itswork roll comprises a pawl and ratchet drive, or other suitable types ofone-way drives may be employed if desired. In the drive shown a ratchet27 is connected by suitable coupling to the roll while pivoted pawls 28carried by the gear wheel cooperate with this ratchet to form a positivedrive for the respective work rolls, but will permit the rolls to rotatefaster than this drive under the action of the strip of metal as it isdrawn through by the blocker. This mill may, therefore, be used as aregular rolling mill with a positive drive for the work rolls or it maybe used as a drawing mill where the metal is drawn through by a separatedevice. The pa'wls 28 are held in engagement with the ratchet bysuitable springs 29.

In case the mill is used as a drawing mill the positive drive for therolls will roll the forward end of the strip until it reaches theblocker and is gripped thereby and then the blocker will draw this stripthrough the rolls. Therefore, the entire length of the strip will berolled to the proper gauge and it is not necessary to shift the rollsand set them for each individual strip. In old types of drawing mills itwas necessary to separate the rolls in order to feed the strip to theblocker, then the rolls had to be reset to the proper gauge. Thisrequired considerable time and also was siderable length at its forwardend which was not rolled to the same gauge as the rest of the strip,.andtherefore, there was a length of several feet which had to be placed inthe scrlap. These objections are obviated by my mi 1.

In Fig. 2, I have shown a slightly difierent arrangement of drive. Inthis arrangement both the work rolls are driven from the same end orside of the housing and they are given suitable relative speeds by theintermeshing gears 30 and 31 of any suitable type, such as the usualherringbone gear, connected with the respective rolls by the couplings32, 33 and connecting bar 34. One of these couplings is a one-way drivethe same as used in the arrangement of Fig. 1 and it may be a pawl andratchet drive the same as in the first form. The ratchet 37 is connectedto one of the elements while the pawls 35 are connected to the otherelement and are held in engagement with the ratchet by the springs 36.This gives the same one-way drive as used in the first form and willslip to allow the work rolls 11 and 12 to run faster than they wouldunder the action of a positive drive the same as they would in the firstform. It will be understood the gears 30 and 31 are proportioned to givesubstantially the same surface speed to the two work rolls. Here as inthe other form, we can drive either of the work rolls or the backingrolls in the start of the rolling operation. Then after a suitablelength has been rolled the block pulls the metal through. This operationcan be secured with a fourhigh mill, a three-high mill, or a two-highmill. In case the backing roll or rolls is or are driven the one-way orratchet drive is in the drive for the backing roll. When the blockbegins to pull on the strip then the one-way drive slips.

It will be obvious from the foregoing description that with acomparatively simple construction I have produced a rolling mill whichmay be used either as an ordinary rolling mill with a positive drive orit may be used as a drawing mill. Also with the use of relatively smallwork rolls I can secure large reductions with a single pass, and byusing work rolls of ditferentdiameters I obviate the sticking or weldingof the hot plates together when the mill is used for rolling hot sheetsin stacks.

Having thus set forth the nature of my invention, what I claim is:

1. In a rolling mill for flat sheetmetal, a pair of cylindrical workrolls of diiierent diameters. a one-way positive drivefor one of saidrolls, and means for drawing a tint strip between the rolls at a greaterspeed than is given the roll by said drive so that the strip is drawnbetween the rolls solely by the pull of the drawing means.

2. In a rolling mill for tint sheet metal, a air of cylindrical workrolls of diiterent iameters, a one-way positive drive for each of saidrolls, and means for drawing a fiat strip between the rolls at a greaterspeed than is given by said drive so that the metal isdrawn through therolls independently of the drive for the rolls.

3. In a rolling mill for flat sheet metal, a pair of work rolls ofdifferent diameters, a one-way ratchet drive for one of the work rollsto positively drive said roll in one direction only, a blocker adaptedto grip a flat strip and 'draw it between the work rolls, and means fordriving the blocker at a greater surface speed than the work rolls sothat the metal is pulled through the rolls by the blockerindependentlyof the drive for the rolls;

4. In a rolling mill for flat sheet metal, a pair of work rolls ofditlerent diameters, an undriven backing roll for the smaller work roll,roller bearings for the necks of the backing roll so that it is free torun at the same surface speed as the work roll, a oneway ratchet drivefor one of the working rolls to positively drive said roll in onedirection only, a rotary blocker adapted to grip a fiat strip and drawit between the work rolls, and means for drivin the blocker at surfacespeed greater than t mt of the work rolls so that the metal is drawnbetween the rolls h the block independently of the. drive for t 1e roll.

5. In a rolling mill,'a pair of work rolls of relatively small diameter,an undriven hacking roll for each work roll of relatively largediameter, roller bearings for the bacle in rolls so that the backingrolls form roller bearings for the work rolls, a one-wa posi tive drivefor each work roll, a rotary locker adapted to grip a strip of metal anddraw it between the work rolls, and means for driving the blocker todraw oil? the metal at a, greater speed than the driven speed of thework rolls so that the metal is drawn through the rolls independently ofthe drive for the rolls.

6. In a rolling mill for flat sheet metal, a pair of cooperatingcylindrical work rolls of different diameters on opposite sides of thework and capable of rolling a plurality of superimposed flat strips,means for driving the rolls to roll the be inning end ortion of thestrip to gauge, an means for t Ien drawing the superimposed stripsbetween the rolls independently of other driving means for the rolls.

7. The method of rolling a plurality of flat metal strips in supcrimiosed relation which comprises nissing the e innin end portion betweentll\'(ll cylindrical ro is of different diameters and then pulling there maindor of the strips through the rolls independently of otherdriving means for the rolls.

8. In a rolling mill for flat steel metal, a pair of eylindrirul workrolls, a drive for one of the rolls so as to roll to gauge the beginningend portion of a flat strip, a roller for coilin the strip afteritlenves the rolls, and means for driving the coilnr at a greatersurface speed than said drive gives the roll so that the remainder ofthe strip is drawn between the rolls by said ooiler independently of thedrive for the roll.

9. In a rolling mill for flat sheet metal, a pair of relutivel y smalleylindrioul work rolls, u drive for one of said rolls so as to roll togauge the beginning end portion of a flat el rip. undriven untifrietionbacking rolls for the work rolls, and means for drawing the remainder ofstrip between the rolls at a greater speed than is given by said'iiriveand indepomloutly of said drive.

it). -In 11 rolling mill, a pair of cylindrical work rolls of dill'orentdiameters capable of rolling u plurality of superimposed strips, adriving menus for one of the rolls cupab e of passing the metal betweenthe rolls, an un driven anti-friction hacking roll of relatively largediameter for the smaller work roll, und menus for drawing the suwrimposed strips between the work rolls at a greater surface speed thansaid drive.

11. In a rolling mill for flat. sheet. metal, a pair of cylindrical workrolls, a one-way rutzeln-t drive for one of the rolls so that the rollmay be positively driven in one direction only, an anti-friction buckingroll for each work roll, u blocker urrungod to grip a flat strip andpull it between the rolls, and means for driving the blocker at agreater surface speed than the rolls.

12. A method of rolling a flat metul strip which comprises rolling ashort length of the end portion of the strip between power drivencylindrical rolls and then winding the strip on a block and drivingthoblock at a greater surface speml than the power driven speed of therolls so that the pull of the block is the driving: means for the rollsfor rolling the renuiinder of the strip.

13. In a rolling mill for flat sheet metal, a pair of cylindrical. workrolls of relatively small diameter, a power drive for one of said rollsto roll the end portion of a strip, a ooilor III for coiling theflatstrip after it leaves the rollm and means for driving the eoiler ata greater surface speed than the power drive gives the roll so that theremainder of the strip is (1m \vn between the rolls by said coiierindependently of the rell drive.

In testimony whereof I afiix 111v signature.

CHARLES. J. GEBBONS.

